Report on Manam (Papua New Guinea) — June 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 6 (June 1989)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Fewer earthquakes; slow deflation continues
Please cite this report as:
Global Volcanism Program, 1989. Report on Manam (Papua New Guinea) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 14:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198906-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Activity was at a very low level throughout June. Southern Crater released white to grey vapour [and ash] in weak to moderate amounts. Weak deep rumbling noises were occasionally heard. Main Crater released weak emissions of white vapour. The seismicity fluctuated at a somewhat lower level than 'normal' inter-eruptive rates, between 500 and 1,100 minor events/day. Tilt readings also fluctuated, although continuing on a slow deflationary trend since early March."
Geologic Background. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys" channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Information Contacts: P. de Saint-Ours and B. Talai, RVO.